Visible hematuria in the naked eye may be caused by urinary tract infection, prostate hyperplasia, urinary stones and renal cysts. In addition, patients with IgA nephropathy can also show hematuria in the naked eye. 1. Urinary system infection: If the patient has infection in the urinary system, such as acute urinary tract infection, acute pyelonephritis, cystitis, renal tuberculosis and other diseases, the symptom of hematuria visible to the naked eye will appear. 2. Prostatic hyperplasia: hematuria visible to the naked eye may be caused by prostatic hyperplasia, due to the increase in the size of the prostate gland, resulting in surface vascular varicose rupture and bleeding, manifested as hematuria visible to the naked eye or blood dripping from the urethra and other symptoms. 3. urinary stones: stones in the urinary tract lumen will rub the wall of the urinary tract lumen, which can easily cause damage to the mucous membrane of the urinary tract, resulting in bleeding of the mucous membrane, the phenomenon of hematuria visible to the naked eye. 4. Renal cysts: renal cysts gradually increase in size, and the blood vessels around the cysts rupture, which leads to the symptom of hematuria in the naked eye. In addition, patients with IgA nephropathy can also show hematuria. It is recommended to go to the hospital in time to do the relevant examination when the symptom of hematuria is visible to the naked eye, so as to clarify the cause of the disease and then under the guidance of the doctor for reasonable treatment.